clinton, who later presented him with the congressional gold medal. mandela stepped down as president in 1999, but he lived long enough to see the united states elect its own black president. >> so help me god. >> reporter: and in 2011 he was paid a visit in south africa by first lady michelle obama who brought along first daughters malia and sasha. admired around the world and revered at home, nelson mandela's south africa embraced a multiracial future and re-entered the family of nations. he leaves a legacy of freedom and proof that one life can make a difference. >> we are one country, we are one people. >> reporter: brian williams, nbc news, new york. >>> we'll have much more on mandela's death in just a moment, but first, a massive winter storm is blasting its way across much of the country. in oklahoma, a number of accidents have been reported due to the recent snow accumulation. temperatures in missouri hit so low that roads became sheets of ice leaving drivers sliding all over the place. now for a look at the national forecast, bill karins is